Closes#122
Both prod and dev environments use PostgreSQL. Removes all SQLite
compatibility code that was never exercised in practice.
Changes:
- db_engine.py: replace SQLite/PostgreSQL branching with direct
PooledPostgresqlDatabase init; remove DATABASE_TYPE, SKIP_TABLE_CREATION,
all db.create_tables() calls, and commented-out SQLite scout_db code
- db_helpers.py: remove DATABASE_TYPE var and SQLite on_conflict_replace
branch from upsert_many(); PostgreSQL ON CONFLICT is now the only path
- players.py: update stale comment
- tests/conftest.py: remove DATABASE_TYPE env var (no longer needed);
keep POSTGRES_PASSWORD dummy for instantiation
- CLAUDE.md: update SQLite references to PostgreSQL
Note: unit tests in test_evolution_seed.py and test_season_stats_model.py
use SqliteDatabase(':memory:') for test isolation — this is legitimate test
infrastructure, not production SQLite compatibility code.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
